I think Eliana is the best spelling, and I like the el-ee-AH-na pronunciation (rather than ellie-anna.)
I like the name, but it seems a bit blendy to me- it sounds a lot like Ellie, Alana, Elena, Ariana, Adriana, etc.

To me Eliana is pronounced El ee On ah and Elianna would be El ee Anna. I used to babysit a little girl name Eliana and I think it is a beautiful name. My daughter is Liana because I loved Eliana but we were naming after someone and needed an L name.